Roddy, it is 25 years since The Commitments was published as a novel, why the decision now to turn it into a musical?

Well, it was a long dawning on me. There was interest in it immediately after the film came out and, at that time, I think I was just keen to get on with other work. So I ignored The Commitments for years and wrote I don’t know how many novels and screenplays.

I didn’t look at The Commitments again until my two sons, who are now in their twenties… sometime in their teens they’d watched The Commitments and had enjoyed it. They didn’t realise that I had written it. So I watched it with them and began to feel quite proprietorial about it. I’d forgotten a lot of the lines in it.

Again, as they got older, I started going to musicals. Once or twice a year we’d come over here (to London), go to a football match in the afternoon and a show in the evening like hundreds of thousands of other families. And I enjoyed that and I began to open up my mind to the notion of The Commitments musical.

So at one point my agent and I just got out the old files and looked up all the people that had been in touch over the past 20-odd years and contacted them and said, ‘if you’re still interested, we can meet. So we met a whole host of American, British and Irish producers and just eventually decided on Phil McIntyre (the musical’s producer).

Is it quite daunting to be premiering it straight in the West End? Were you tempted to try it out somewhere else first?

No. Again I feel like…I’ve a novel out in August and it won’t be opening up in a shop in Ipswich first and gradually working its way down to bigger cities. I know the two forms are different, but I find the notion a bit strange. I feel that it’s always a bit of a gamble but, if we do a good job, then it doesn’t matter where we open.

That’s one of the things that I liked about Phil (McIntyre) was that he was very confident about opening in London. When we asked him if we should open somewhere else and work our way down to London he said, ‘no, why would you? Everybody knows the story, so if you do it well why not just open in London’. That seemed to make sense to me.

Have you had any input in the main roles?

No. I wasn’t involved in the casting. They (the creative team) were over in Dublin for a while to hold auditions. I dropped down for an afternoon to see it and I enjoyed it. I won’t be working with the cast, although I will be down at rehearsals. That’s the director’s job.

Himself and the musical director have chosen people that they know will do a job. It seems to me that the spirit of the original work is there. The book was about a bunch of kids in Dublin who form a band.

One of the reasons that I think the film became popular was that it didn’t have well-known faces pretending that they were kids from Dublin – and not all of them were from Dublin. But they did a good job. I think that this will be the same. I think that it would be a mistake if you had a whole rake of familiar people from shows or from television. That’s not the route that’s been taken.

In terms of the adaptation, how did you feel about going back to the work?

Well it was actually easy enough in so far as I wrote the book 27 years ago. It’s literally half me life away so I was 27 at the time. I have no idea what I was like back then. I have no idea what made me write an individual line. I hadn’t read the book in more than two decades.

I was coming over here for a meeting about The Commitments and so I thought I should read the book. So I read it on the plane, because it’s pretty short. And I was laughing in a way that I don’t usually do with my own work. But it didn’t feel like my own work because it was so long ago. The characters just seemed so different.

I was a bit worried about dialogue because the way people speak changes subtly. I wouldn’t be the same if I had a bunch of kids and set the story in Dublin in 2013. Essentially they could be the same but there would be little rhythms and words that wouldn’t have been around 27 years ago.

But actually I was quite surprised that there was a timeless element to the dialogue, that actually most of the lines you could almost superimpose today and they’d work. It’s other things that would actually wreck the story somewhat.

If Jimmy Rabbitte had a mobile phone, the story wouldn’t happen. You could still form the band but he’d be sitting in a corner there and he could do all his work while doing other things at the same time. And there’d be no having to go from A to B, to A to B, to A to B.

There’d be no gamble either as to if they’d turn up. You’d get these texts ‘on the way, the bus is late. Xx’. You know these sort of things? It would be slightly different. I struck me that this bunch of young people that tried to form a band is essentially the same story that’s been going on since the first guitar was bought.

I remember meeting someone a few years ago that said kids just join bands anymore. I couldn’t believe it just on the evidence of my own eyes, with my own kids. They’re in and out of bands like they’re in and out of doors! It’s that frequent. I found that reassuring.

Are you worried that the musical will be unfairly judged against the film or the novel?

Well the hope would be that we do it properly. It’s a big ‘if’ at the moment because it’s April and it won’t go until October but the hope would be that people would forget the film and the book fairly quickly, if they’re familiar with it.

It’s a bit like Billy Elliott. I’d seen the movie and I really like it, but I forgot the movie existed fairly quickly when I was watching the musical. It was an entirely different experience. We’re basing it on the book so you won’t get the visuals of the film. Same story and same plot but in other ways it will be completely different. We’ve freedom of choosing songs as well so the running order of those will be different. Hopefully people will just sit and watch the show.

Why do you think, above all your other work, people have connected with The Commitments?

Well it’s the music for a start, and I think that it’s the simplicity of the story. Within us all there’s the wish to be in a band or to have been in a band. It’s the same with football. I don’t know if you’ll reach an age where you’ll be watching a game and the little lad inside you won’t come out to say, ‘I could do better than that’. I think there’s an element of that in everyone. But it’s a simple story and it’s funny. That’s what the appeal is, I think.

You’ve also written a sequel to The Commitments called The Guts…

It’s not a sequel as such. A sequel to The Commitments would imply that The Commitments have reformed. No, it’s a book from the point of view of Jimmy Rabbitte as a 48-year-old man.

I think, because of the new recession, I tried to think of how the characters we knew it the last one were getting on, when we didn’t even know it was a recession. It was just normal life in Ireland.

So I went to Jimmy Rabbitte as a 48-year-old man and had a look at him and the pressures of life and family. What’s he doing in life? What’s he doing to fill the fridge? That sort of thing. It’s coming out in August, when I’m in rehearsals for the musical, so I’ve got Jimmy as a 21-year-old and Jimmy as a 48-year-old. It’s great!

I guess it’s a funny coincidence that across the road from where The Commitments will be staged your former student, Enda Walsh, has his name in lights as the playwright who has adapted Once for the stage?

Yeah. Ha! I haven’t seen Enda for a while actually. There was some talk about us doing an ‘In Conversation With…’ event in July but unfortunately I’ll be on holiday. But I always get a thrill when I see Enda’s name involved in anything. His work has got become more diverse in recent years, which is great.

Do you remember him from your teaching days at Greendale Community School in Kilbarrack, Dublin?

I do. I went to school with his older brother John. We were in primary school together. Enda was in the very first class I taught in 1979. He was in his first year in secondary school and I was just starting my teacher training. So this smaller version of his brother walked into the room. I was 21 and Enda would have been 12. So yeah, I do recall him. I recall them all. I then ended up teaching him every year throughout his time in the school. He was a terrific student.

Have you seen Once?

Not yet but I’ll be in London quite a lot over the summer so I’ll catch it then.

On the £5 preview tickets, I know through other work you’re involved in that you would seem keen that art shouldn’t just be for the elite or those that can afford it?

Yeah, it just makes sense. Obviously to put on a big show like this with a big cast and in a theatre like this (the Palace Theatre) there are commercial considerations. You have to be able to do it in a way that makes commercial sense. I understand that.

Now, when I’m writing the thing I shouldn’t be worried about that at all. It shouldn’t be my job, but I think that if you can do it that people can get in relatively cheaply, I think that it’s fantastic. I don’t know anybody creatively involved in the arts that would feel a certain type of person would be excluded from their work. It doesn’t make any sense, so if you can allow people to get to the show for relatively little, I think that’s great.

Do you think that it’s going to change the dynamic of the audience at the shows?

Well I had a play on in Dublin years ago. It was the first play I ever had and there were tickets that were very, very cheap and it did actually have a huge impact on the type of people who came to the play.

They were out for the night; they brought their own sweets; they didn’t care much for the conventions – that you clap at some place and that you stay silent during another, all those conventions we learn as we go to plays. So there was a certain wildness in the audience that was great for that particular show. So I imagine the same thing, that if we do a good show this time around the reaction from the audience should be great.

Will the show eventually make its way to Dublin?

I’m sure there’s a desire to bring it there but from my point-of-view, if I don’t personally do a good job, collectively we won’t do a good job and it won’t be going anywhere. So my job now is to focus on the work. I could dream away of playing for Chelsea, but it’s not going to happen, no more than if I don’t actually concentrate on the quality of the work. But it would be a great night for me if it opens in Dublin, but that’s not a plan. Nobody has mentioned it to me.

The Commitments opens at the Palace Theatre, London on October 8. Previews begin on September 21 with all preview tickets half-price and starting at £5.